Dörr photographed 46 influential women, from Oprah Winfrey and Serena Williams to Hillary Clinton and Selna Gomez, for the magazine. The magazine published a piece called “Firsts,” which featured women who are changing the world.

The 28-year-old Brazilian photographer began using an iPhone in 2012 and it immediately became a complement to her daily equipment. In an interview with Time’s LightBox, Dörr said:

“Suddenly, I was able to make great pictures anytime, anywhere, without the stress of carrying a bag full of lenses, cards, and batteries. You usually see photographs of these women with lots of production and lighting. For me, it is difficult to be inspired by a portrait of someone who seems unreachable

For Firsts, the pictures are made with natural light, using only a reflector when necessary. I Like the simplicity of how these pictures are made. But the best part is that as a photographer, you feel extremely light and free. It is almost as if I can make pictures with my hand. There’s no noise, gadgets, tools or plugs – just the subject and myself.”

Dörr said some shoots presented lighting challenges that reflectors could not overcome. On occasion, she used automatic HDR to gain a greater range of light and details.

Tim Cook posted a tweet commemorating Dörr for her great photography work.

Kira Pollack, Time’s director of photography and visual enterprise, had never heard of Dörr when she discovered her work last year scrolling through Instagram. Captivated by the portrait on her Instagram feed, she tracked down Dörr and offered her the assignment.